This invention relates to communication system call conference control arrangement and more particularly to an arrangement for controlling conference calls in a stored program controlled communication system.
Problems exist in telephone communication systems when it is desired to establish conferences between more than two stations. Primarily, these problems arise from the desire to allow any station to have the ability to add on an additional station to an existing calling connection without the use of externally provided assistance. In some presently known systems the station user flashes the switchhook to obtain operator assistance when such a conference is desired. When a new party is to be added or when a party is to be removed from the conference the assistance of the attendant is required. This is both time consuming, inefficient and not always practical.
In other known systems conferencing can be established under control of one of the parties to the call by first flashing the switchhook, obtaining dial tone, dialing the desired number and then flashing the switchhook to bridge the two calling connections. Once such a bridging occurs, it is difficult to separate the parties. When more than three parties have been involved in a conference the problems become compounded. If a flash is too long, parties may be inadvertently dropped.
Thus it is desired and it is a general object of our invention to arrange a communication system with conference establishing control such that any station, without external assistance, may set up (add) or tear down (subtract) a conference with any number of other parties up to a preset maximum, easily, efficiently, and without confusion.